Are there any amplifiers in your system? If yes, see below.
Confirm the remote turn-on wire is connected to the corresponding wire on the vehicle harness. This is either labeled “Remote” or “AMP Turn On” and is usually blue or blue with a white stripe.
If there are no amplifiers in your system, see below.
You can test if the problem is with the receiver by testing the receiver with a spare speaker that is NOT connected to the vehicle. Connect the speaker directly to the receivers Front Speaker wires of the head unit. If you do not receive sound, then the receiver will need to be replaced. If you do receive sound, then the issue is with the vehicle’s internal amp or possibly a defective 3rd party wiring interface.